Tracheal catheter and prosthesis and method of respiratory support of a patient

ABSTRACT

A method and apparatus is described for supporting the respiration of a patient. The spontaneous respiration of a patient can be detected by sensors and during inhalation an additional amount of oxygen can be administered to the lungs via a jet gas current. If required, during exhalation a countercurrent can be administered to avoid collapse of the respiration paths. This therapy can be realized by an apparatus including a transtracheal catheter, an oxygen pump connected to an oxygen source, spontaneous respiration sensor(s) connected to a control unit for activating the oxygen pump and, if needed, a tracheal prosthesis. The tracheal prosthesis may include a connection for the catheter and the breath sensor(s). The tracheal prosthesis, if used, and the catheter can be dimensioned so the patient can freely breathe, cough, swallow and speak without restriction, and the system can be wearable to promote mobility.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.10/771,803, filed Feb. 4, 2004, which claims the benefit of priorityunder 35 U.S.C. § 119 to co-pending German Patent Application Serial No.10337138.9, filed Aug. 11, 2003, the contents of each of which isincorporated herein in its entirety.

FIELD OF INVENTION

The present invention relates generally to respiratory systems directedand more particularly to specialized mechanisms for enhanced ventilationof a patient.

BACKGROUND OF THE INVENTION

In order that the body can take in oxygen and give off carbon dioxide,both components of the respiratory bronchial system must function—thelungs as a gas-exchanging organ and the respiratory pump as aventilation organ that transports air into the lungs and back out again.The breathing center in the brain, central and peripheral nerves, theosseous thorax and the breathing musculature as well as free, stablerespiratory paths are necessary for a correct functioning of therespiratory pump.

In certain diseases there is a constant overload on or exhaustion of therespiratory pump. A typical syndrome is pulmonary emphysema withflat-standing diaphragms without the ability to contract. In the case ofpulmonary emphysema the respiratory paths are usually extremely slackand tend to collapse. As a consequence of the flattened, over-extendeddiaphragms the patient cannot inhale deep enough. In addition, thepatient cannot exhale sufficiently on account of the collapsingrespiratory paths. This results in an insufficient respiration with anundersupply of oxygen and a rise of carbon dioxide in the blood, theso-called ventilatory insufficiency.

The treatment for inhalation difficulty often makes use of a breathingdevice. The so-called home respiration is an artificial respiration forsupporting or completely relieving the respiratory pump.

The respiration can take place non-invasively via a tube and a nose maskor mouth mask that the patient can put on and take off as needed.However, this prevents the patient from breathing freely and speakingfreely. In addition, a blocked tracheal cannula can be inserted into thetrachea. This also has the consequence that the patient can no longerspeak.

In the case of invasive respiration this usually occurs via atracheostomy. This involves an opening placed in the trachea by anoperation. A catheter about the diameter of a finger with a blockingballoon is inserted via the opening into the trachea and connected to abreathing apparatus. This makes a sufficiently deep respiration possiblebut prevents the patient from speaking. In addition to the respirationthere is the transtracheal administration of oxygen via thinnercatheters. U.S. Pat. Nos. 5,181,509 or 5,279,288 disclose correspondingembodiments. In this manner a highly dosed administration of oxygen isadministered to the patient in a continuous stream with a permanentlyadjusted frequency. The flow of oxygen is regulated manually by athrottle device. However, simulation of the natural breathing process ofa patient is not achieved because breathing is not deep enough. Also,the catheter end introduced into the trachea can result in irritationsand a local traumatizing of the surrounding tissue in that it strikesagainst the trachea as a consequence of the respiratory movement or inthat the surrounding tissue is dried out by the jet stream.

Furthermore, so-called “Montgomery T-tubes” are known that are insertedinto the trachea. The patient can obtain oxygen via the shank of theT-piece run to the outside. In addition, the patient can draw offsecretions himself if needed. The patient can breathe freely and speakwhen the front shank is closed; however, respiration is not possible viathe Montgomery T-tube since the introduced air escapes upward into thebuccal cavity or the pharyngeal area. An additional limitation of theabove-referenced therapies is the impaired mobility of the patientbecause of inadequate ventilation as well as the bulk of the apparatus.

Therefore, there is an existing need for a respiratory system thatprovides a more efficient method for supporting the respiration of apatient and of creating an apparatus to this end that can also be takenalong by the patient and is reliable in its use. Moreover, the there isa need for a tracheal prosthesis and a catheter that make possible arespiratory support synchronized with the spontaneous respiration of thepatient without adversely affecting the patient's ability to speak.

SUMMARY OF EXEMPLARY EMBODIMENTS

It is a principal objective of the present invention to provide anapparatus and method that improves the quality of life of patients thatrequire respiratory support. In the furtherance of this and otherobjectives, the present inventor provides a respiratory system thatprovides a more efficient method of supporting the respiration of apatient by providing additional oxygen when needed.

I is an additional objective in accordance with the present invention toprovide as system that is portable and reliable in its use.

Yet another objective in accordance with the present invention is toprovide a tracheal prosthesis and a catheter that make possible arespiratory support synchronized with the spontaneous respiration of thepatient without adversely affecting the patient's ability to speak.

Further objectives, features and advantages of the invention will beapparent from the following detailed description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the upper body of a patient carrying an apparatus inaccordance with the invention for respiration support.

FIG. 2 shows a diagram with a view of the respiration flow of anemphysema patient with and without respiration support.

FIG. 3 shows a technically simplified view of a tracheal prosthesis inaccordance with the invention.

FIG. 4 shows another embodiment of a tracheal prosthesis.

FIG. 5 shows, also in a scheme, an oxygen pump belonging to theapparatus of the invention showing the conduction of air and a controlunit.

FIG. 6 shows the end section of a catheter in accordance with theinvention.

FIG. 7 shows the catheter according to FIG. 6 inserted in a supportbody.

DETAILED DESCRIPTION OF AN EMBODIMENT

The present invention, in a preferred embodiment, provides an apparatusfor supporting the respiration of a patient and to a trachealprosthesis. According to the invention the spontaneous respiration of apatient is detected by sensors and at the end of an inhalation procedurean additional amount of oxygen is administered to the lungs via a jetgas current. This improves the absorption of oxygen during inhalation.If required, the exhalation procedure of the patient can be arrested orslowed by a countercurrent in order to avoid a collapse of therespiration paths in this manner. This procedure is realized by anapparatus comprising an oxygen pump that can be connected to an oxygensource and comprising a tracheal prosthesis that can be connected via acatheter. The spontaneous respiration of the patient is detected bysensors connected to a control unit for activating the oxygen pump. Thetracheal prosthesis comprises a tubular support body with a connectionfor the catheter and two of the sensors are associated with the supportbody. The tracheal prosthesis and the jet catheter that is integrated orcan be introduced are dimensioned in such a manner that the patient canfreely breath and speak without restriction.

Referring specifically to FIG. 1, P designates a patient suffering froma pulmonary emphysema with an overloading and exhaustion of therespiratory pump. As a consequence, the patient can not inhale deeplyenough. In addition, the exhalation process is hindered by slack andcollapsing respiratory paths.

Such a respiration process with inhalation/inspiratory flow andexhalation (expiratory flow) without respiratory support is shown inFIG. 2 in the left half of the image. The curve for inhalation isdesignated by E1 and the curve for exhalation by A1.

In order to support and relieve the strain on the respiratory pump thepatient's spontaneous respiration is detected by sensor and at the endof an inhalation process of the lungs an additional amount of oxygen isadministered. This respiratory flow is illustrated in the right half ofFIG. 2. The additional amount of oxygen increases the respiratory volumeduring inhalation according to curve E2 by the difference volume showndarkened in the upper curve and designated by E3. The additional amountof oxygen can have a volume between 25 ml and 150 ml.

In addition, the exhalation process of the patient is braked by acountercurrent. As a consequence thereof, the respiratory flow shiftsduring exhalation along the curved designated by A2. This purposefulresistance acting opposite to the exhalation prevents a collapsing ofthe respiratory paths during exhalation. In this manner the exhalationvolume is increased by the volume also shown darkened and designated byA3.

As a consequence, this method avoids an insufficient respiration with anundersupply of oxygen and an increase of carbon dioxide in the blood.Patient P is significantly less stressed and more mobile and in additionhe perceives less or no shortage of air.

In order to carry out the respiration support of patient P, an apparatusis provided comprising oxygen pump 1 that can be connected to an oxygensource (see FIG. 5) and comprising tracheal prosthesis 2, 3 (see FIGS.3, 4). According to FIG. 1 oxygen pump 1 is a component of a compact,mobile respiration device 4. Oxygen pump 1 and tracheal prosthesis 2, 3are connected via catheter 5.

As FIGS. 3, 4 show, each tracheal prosthesis 2, 3 comprises tubularsupport body 6 with connection 7 for catheter 5. In order to detect thespontaneous respiration of patient P two sensors 8, 9 in the form ofthermistors are associated with support body 6. One sensor 8 is fixed oninner wall 10 of support body 6 and the other sensor 9 is located onouter wall 11 of support body 6. Sensors 8, 9 communicate with controlunit 12 for activating oxygen pump 2. Control unit 12 is schematicallyshown in FIG. 5 with its inputs and outputs. As already stated, sensors8, 9 are thermistors, that is, temperature-dependent resistors. They areconnected together in a bridge circuit in the apparatus so that acompensation of measured value differences between inner sensor 8 andouter sensor takes place as a consequence of environmental influences.

FIG. 1 also shows that other respiration sensors 13, 14 are provided.They are also sensors for detecting the spontaneous respiration ofpatient P. An exact image of the respiration process of patient P can beobtained by adjusting the measured values received via sensors 8, 9 and13, 14. In addition, the safety against false measurements or thefailure of one of sensors 8, 9 and/or 13, 14 is increased.

In tracheal prosthesis 2 according to FIG. 3 the jet catheter 5 can beinserted via connection 7 into support body 6. End 15 of jet catheter 5located in support body 6 is guided or deflected approximately parallelto its longitudinal axis L. The data lines from sensors 8, 9 to controlunit 12 are designated with 16, 17 running inside catheter 5. On thedischarge side the end 15 of jet catheter 5 is designed as jet nozzle25. This can take place by reducing the cross section of the catheter.This increases the speed of the oxygen current at the discharge fromcatheter 5 and it is conducted in the direction of the bronchial tract.The diameter of support body 6 is dimensioned with a sufficiently freelumen in such a manner that patient P can freely breathe and speak evenwith integrated catheter 5.

Separate coupling 18 is provided on connection 7 in tracheal prosthesis3 according to FIG. 4 via which catheter 5 is connected to trachealprosthesis 3. In this instance fixed longitudinal section 19 alignedparallel to longitudinal axis L is provided as catheter end in supportbody 6 and the oxygen current is conducted via jet nozzle 26 in thedirection of the bronchial tract.

Oxygen pump 1 is schematically shown in FIG. 5. It is a piston pump withdouble-acting piston 20 arranged in cylinder 27. The apparatus comprisesfour valves V1 to V4. The supply of oxygen takes place from an externaloxygen reservoir via connection 21. The switching states of valves V1 toV4 and the supply lines and removal lines are designated by letters a tog.

Oxygen pump 1 functions in the apparatus during the support ofrespiration as follows: When valve V1 is open from c to a (b to cclosed) and valve V2 open from b to e (e to d closed), piston 20 movesto the left in the plane of the figure and the oxygen flows via outlet22 and jet catheter 5 to patient P. The additional amount of oxygen E3is administered during the inhalation process of patient P.

When valve V1 is open from b to c (c to a closed) and valve V2 is openfrom e to d (b to e closed), piston 20 moves to the right in the planeof the figure in the flow of oxygen takes place in the direction ofvalve V3. Valve V3 is connected to the ambient air via outlet 23. In theinstance in which valve V3 is open from d to g the oxygen flows offwithout expiration brake. That means that the exhalation process is notbraked by a countercurrent.

If valve V3 is closed from d to g and open from d to f the oxygen flowsvia access path 24 in the direction of outlet 22 and catheter 5 in orderto be administered to patient P during the exhalation process and inorder to break the respiratory flow. The countercurrent prevents acollapsing of the respiratory paths and keeps them open. This makes adeeper exhalation possible.

Furthermore, valve V4 is located in access path 24 of the apparatus, viawhich the flowthrough (f to a) can be variably adjusted. This canadvantageously be a proportional valve with pulse-width modulation.

FIG. 6 shows catheter 28 with long, flexible tube 29 and end 31 on thedischarge side bent in curvature 30. Two sensors 32, 33 for detectingthe spontaneous respiration of patient P are fastened on the end.Sensors 32, 33 are preferably thermistors. Data lines are not shown inthe drawing for the sake of simplicity. They run through catheter 28 andthe catheter wall. 34 designates a stop.

It can also be seen that end 31 of catheter 28 is provided with jetnozzle 35. The cross section of the flow is reduced relative to thecross section of the catheter in jet nozzle 35 so that the dischargerate of the supplied oxygen is increased.

Catheter 28 can be introduced into support body 36, as FIG. 7 shows.Support body 35 is located in the trachea of patient P. The connectionto the outside is established via connection 37. Support body 36 can bea traditional Montgomery T-stent.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrative,and not restrictive. The scope of the invention is, therefore, indicatedby the appended claims, rather than by the foregoing description. Allchanges, which come within the meaning and range of equivalency of theclaims, are to be embraced within their scope.

1. A method for supporting the respiration of a patient comprising thesteps of: detecting the spontaneous respiration of the patient is bysensors; identifying the end of the inhalation process; andadministering an additional amount of oxygen to the lungs.
 2. The methodof claim 1, wherein the additional amount of oxygen is administered atthe end of an inhalation process.
 3. The method of claim 1, wherein theamount of oxygen has a volume of about between 25 ml-150 ml.
 4. Themethod of claim 2, wherein the amount of oxygen has a volume of aboutbetween 25 ml-150 ml.
 5. The method of claim 1, further comprising thestep of braking the exhalation process of the patient with acountercurrent.
 6. The method of claim 2, further comprising the step ofbraking the exhalation process of the patient with a countercurrent. 7.An apparatus for supporting the respiration of a patient that comprisesan oxygen pump operatively connected to an oxygen source, the apparatusfurther comprising sensors for detecting the spontaneous respiration ofthe patient, the sensors are connected to a control unit for activatingthe oxygen pump.
 8. The apparatus of claim 7, wherein the oxygen pumpcomprises a tracheal prosthesis connectable by a catheter, the trachealprosthesis having a tubular support body with a connection for thecatheter.
 9. The apparatus of claim 8, wherein the sensors areassociated with the support body of the tracheal prosthesis.
 10. Theapparatus of claim 9, wherein at least one sensor is coupled with theinner wall of the support body.
 11. The apparatus of claim 9, whereinthe end of the catheter located in the support body is deflectedapproximately parallel to its longitudinal axis (L) and is provided onthe end with a jet nozzle.
 12. The apparatus of claim 10, wherein theend of the catheter located in the support body is deflectedapproximately parallel to its longitudinal axis and is provided on theend with a jet nozzle.
 13. The apparatus of claim 7, wherein the oxygenpump is a piston pump.
 14. The apparatus of claim 12, wherein the oxygenpump is a piston pump.
 15. The apparatus of claim 8, wherein thecatheter has a double-lumen design.
 16. The apparatus of claim 14,wherein the catheter has a double-lumen design.
 17. The apparatus ofclaim 7, further comprising additional respiration sensors.
 18. Theapparatus of claim 9, further comprising additional respiration sensors.19. A tracheal prosthesis comprising a tubular support body, aconnection for a jet catheter and at least two sensors coupled with thesupport body.
 20. The tracheal prosthesis of claim 19, wherein at leastone of the sensors is coupled with the inner wall of the support body.21. The tracheal prosthesis of claim 19, wherein the catheter isoperatively coupled with the support body.
 22. The tracheal prosthesisof claim 20, wherein the catheter is operatively coupled with thesupport body.
 23. A catheter having a first and second end, one endaffixable by at least one sensor.
 24. The catheter of claim 23, whereinthe at least one end comprises a jet nozzle.
 25. The catheter of claim23, wherein the at least one end has a curved course.
 26. The catheterof claim 24, wherein the at least one end has a curved course.